A non-volatile memory device such as a NAND flash memory includes a memory cell portion and a peripheral portion. The memory cell portion stores data, and the peripheral portion includes a circuit driving the memory cell portion in accordance with signals provided from the outside for writing and erasing data. The advanced shrinking of the memory cell portion, which occupies the most part of the area of the chip, increases a memory capacity of the device. However, it is considered that the shrinking of the memory cell may easily induce a variation of charge amount retained in each memory call, an operating delay, and the like, influencing the performance of the memory device. Thus, a non-volatile memory device and a method for manufacturing the same are required, which has a memory cell capable of retaining data for a long time, and improves the operating speed.